PROBLEM #1 - What sample size is needed to obtain a 90 percent confidence interval for the mean protein content of meat if the estimate is to be within 1 pounds of the true mean value? Assume that the variance is 49 pounds.
PROBLEM #2 - A cable TV company wants to estimate the percentage of cable boxes in use during an evening hour. An approximation is 20 percent. They want the estimate to be at the 95 percent confidence level and within 2 percentage points of the actual proportion. What sample size is needed?